Metal deactivators



Oct. 24, 1 44- E. R. WHITE ETAL 2,351,339

METAL DEACTIVATORS Filed June 8, 1940 Oxgqen obsnrbzd ml. per I grams of oil 0 I0 so e0 Timz of oxidafion, Hours Patented Oct. 24, 1944 Marat. nuc'rrva'roas run 3. Willi Albany, and Ernest 1.. Walters.

San Francisco, Call! alalgnora to Shell Development Company, San Francisco, cure, a

corporation of Delaware Application June a, 1940, Serial No. season, H (cl. 252-51 8 Claims.

This invention relates to a method for the stabilization of organic substances and particularly to the protection or organic substances against deterioration by oxidation which is catalyzed by the presence of or by contact with certain oxidation promoters. An important application of this invention resides in the reduction of the amount of gum formed in gasoline during storage due to the presence or small amounts of certain metals, their compounds or both. An-

other application is as a stabilizer for lubricating oils to retard discoloration, sludge formation, etc.,' due to catalytic oxidation.

It is the purpose of this invention to provide a class of deactivator compound which reduce the catalytic effect of metal oxidation promoters, more particularly of iron, copper, chromium, cobait, lead, and the compounds of copper, chromium, cobalt, and lead. It is another purpose to provide de'activators which when added to organic substances will remain active for a considerable length of time when subjected to oxidizing influences. Still another purpose is to render hydrocarbon oils insensitive to the catalytic oxidation of metals such as iron and copper for invariably during their useful life, the

oils come in contact with one or the other ofthese metals.

Organic substances normally contact metals, or frequently contain small amounts of metals, usually dissolved in the form of a soluble salt, and it has been observed that the presence of such metals frequently has a detrimental effect on the stability of the substances. Inasmuch as bare traces of the metal may be very harmful and since removal of these last traces is extremely diillcult, it is often not possible to eliminate this troublesome catalyst of the oxidation reaction.

It has already been suggested to reduce the susceptibility of organic substances to oxidation induced by the presence of copper, by adding to the organic substances certain deactivators which have the property of rendering the copper inactive. The deactivators heretofore suggested,

comprise products of condensation of one mol of an aliphatic or aromatic primary diamine with two mols of salicylaldehyde or similar compounds. It is known from example, that the addition of these deactivators reduces the gum formation in the presence of dissolved copper as determined by the A. S. T. M. air jet method and also increases the induction period as tested by the Voorhees and Eisinger method described in S. A. E. J. 24, 584 (1929).

We have discovered the compounds, obtained by reacting one mol of an aromatic aldehyde having a hydroxyl radical in ortho position to the carbonyl radical with one mol of an aliphatic compound of not more than 12 carbon atom which may be in a continuous or discon- .tinuous, straight or branched-carbon chain, hav-' ing one and preferably one only primary amine radical 'and preferably at least one hydroxyl radical, under conditions to eliminate water by the interaction of the carbonyl and primary amine radicals, possess the property of deactivating metallic copper, chromium, lead, cobalt.

iron and the compounds 01' copper, chromium, lead and cobalt. Many of these compounds retain their'activity after exposure to oxidizing influences. They have the general formula o-HOX-CH=N-Y wherein X represents an aromatic nucleus, such as benzene, and Y represents an aliphatic radical having from 2 to l2 carbon atoms inclusive and containing a linkage between two carbon atomsof oxygen, sulfur or nitrogen other than the nitrogen and oxygen atoms to which said Y is attached.

The action of our deactivators appears to be specific for certain metals and their compounds. Diflerent types of organic substances may be protected from the catalytic effect of metal oxidation promoters. The deactivators must be at least slightly soluble in the organic substance by itself or in the presence of a mutual solvent. Neutral and basic substances are in general more susceptible to the action of the deactivators than acids.

Aldehydes suitable to form deactivators with said aliphatic alcohols are, for example, salicylaldehyde, the homo-salicyclaldehydes, trimethyl salicylaldehyde, isobutyl salicylaldehyde, ortho hydroxy naphthyl aldehyde, corresponding aldehydes of anthracene, etc. If desired, the aldehydes may contain substitution radicals, such as alkyl, halogen, amino, imino, hydrazine, ether, thioether, etc. radicals.

Aliphatic compounds of not more than 12 carbon atoms having one primary radical amine capable of forming deactivators with the salicylaldehydes mentioned previously are for example. the alkylamines of the general formula NHzR wherein R is an aliphatic radical of 2 to 12 carbon atoms and which may contain the elements oxygen, sulfur and nitrogen, such as ethyl amine, butyl amine, isopiropyl amine, amino ethyl methyl amine, amino propyl methyl amine,

amino isopropyl methyl amine, n-heptyl amine,

amino isoamyl propyl amine, beta amino ethyl ether, amino ethyl isopropyl ether, acetyl acetone amine, amino ethyl thiomethane, amino methyl thiohexane, amino ethyl thiopropane; or the hydroxy alkylamines of general formula wherein R is an aliphatic radical of 2 to 12 carbon atoms and which may contain the elements oxygen, sulfur or nitrogen such as mono ethanolamine, mono butanolamine, mono dodecanolamine, 1 amino 2 pentan'ol, 4 amino 2 pentanol,

hydroxy ethyl amino ethyl ether, hydroxy propyl amino ethyl ether, hydroxy propyl amino butyl ether, hydroxy propyl amino propyl ether, 1 hydroxy 2 methyl butyl amino propyl ether, the corresponding thio and imino ethera, suli'oxides and suli'ones, such as hydroxy ethyl amino ethyl sulfoxidcs, hydroxy butyl amino ethyl sulfone, ketones and thioketones such as amino methyl isopropyl ketone, 1 hydroxy 5 amino pentanone 3, 1' hydroxy 5 amino pentathlonone 3, hydroxy activators is well known and may be illustrated by the following equation:

o-n0c'.m( i nmcinmncimon The aliphatic chain of the amine should contain not more than 12 carbon atoms to produce relatively low molecular weight compounds, because the reaction between deactivator compounds and the metal is apparently one in which two molecules of deactivator are capable oi capturing and deactivating not more than one atom of the metal. It is not therefore desirable to add too great an amount of dead load to the molecule of the deactivator.

The value of compounds as deactivator-s and suppressors of oxidation due to catalytic activity of the metals may be estimated by measuring the activities under at least two conditions, namely, before and after oxidation. Thus, for example, as applied to a gasoline, one may measure first, the extent to which it overcomes the adverse eifect of the metal in lowering the induction period, second, the extent to which it reduces the initial copper dish gum value 01 the gasoline; and third, the extent to which it maintains low copper dish gum alter accelerated oxidation.

To illustrate how the deactivators of this invention suppress the catalytic activity for example of copper, the deactivators were tested in gasoline containing 1 part per million of dissolved In Table 11 below, the deactivation elects e1 mono salicylal beta beta mono amino hydroxy dietbyliminoetheronthecopperdishgumand tarding their eil'ectiveness.

induction periods before and after oxidation of a cracked gasoline are shown.

Table 1! Induction period, (upper dish gum,

hours imp/ ml. Deoctlvsior added 2.5 m n/ill] ml. 1 I

[81011118 No l I. P. M. Alller I 'llz-lr added dissolved lulllal 1 Mrs MRI! copper copper i UXiuhiUr-u Noam... 4.5:; 1,67 60,00 12mm Mono salieylal beta,

beta mono amino hydroxy dlethyl amino ether 5. 17 4.58 11,13 0, m

It will be seen that the deactivator retained its ability to suppress the copper dish gum to the original low concentration even after exposure to oxidation conditions.

The eflect of the deactivator-s in contact with lubricating oil is illustrated by the attached drawing representing a graph wherein is plotted the length of time in hours of oxidation against the amount of oxygen absorbed in the presence 01 metallic iron.

In this test, the oil is exposed to pure oxygen at atmospheric pressure and at a temperature oi? C.

On the ordinate of the graph is plotted the mols of oxygen absorbed, on the abscissa is indicated the time of oxidation. Two curves are shown, curve 1 representing the rate of oxygen absorption in the absence of any deactivator and curve 2 representing the rate of oxygen absorption under identical conditions in the presence of 0.1% by weight of mono salicylal beta, beta mono amino hydroxy diethyl imino ether.

It will be seen that the metallic iron was deactivated ior a considerable length'oi. time under the extremely severe conditions of the test.

Our deactivators also suppress the catalytic oxidation which may be caused by a combination of the various metal oxidation promote'rs. Thus for example, it gasoline containing dissolved copper is stored in an iron drum, our compounds deactivate both the dissolved copper and metallic iron.

Our products are active in various organic substances which are subject to deterioration by oxidation and which substances during their useful life come in contact with any of the metals or their compounds hereinbeiore enumerated. Thus various refined and semi-refined hydrocarbon oils maybe stabilized, such as gasoline, kerosenelspecial boiling point solvents, Diesel fuels, spray oils, lubricating oils, etc., pure hydrocarbons such as benzene, toluene, various liquid olefins, etc. Other substances capable of being protected are for example animal fats and oils, vegetable fats and oils, soaps, photographic developers, both' natural and synthetic sultonated and sultated rubber, various resins, etc.

The presence of antioxidants and other compounds in the substance to be desensitized, which compounds have the property 01' modifying the susceptibility of these substances toward non-catalytic oxidation such as ordinary oxidation inhibitors as used in gasoline, lubricating oil, rubber, tats, maps, etc. may have an influence on the activity of deactivators, promoting or re- The deactivators oi! this invention may be used in conjunction with other addition agents for example, in gasoline, together with anti-knock compounds and anti-oxidants or in lubricating oils together with anti-oxidants, blooming agents, anti-corrosive, extreme pressure compounds, detergents, etc., or in Diesel fuels together with knock suppressors, anti-oxidants, etc. It is, however, desirable that the addition agent shall not raise the acidity of the substance to be desensitized to the point of greatly diminishing the activity of the deactivators.

The amounts of our deactivators to be added to the substances efiectively to suppress the catalytic action of the metals or their compounds will naturally vary with the stability requirements or the treated product, as well as with the amount metal contained in the organic substance if dissolved metal is the source of the instability.

In general quantities ranging from about .01% to 1% are useful and provide the necessary protection, although under certain circumstances, amounts outside of these limits may be used.

The metal deactivators may be added to the organic substances to be stabilized in any desired form. They may be added in solid or liquid form, mixed with other addition agents or dissolved in a solvent.

Some organic substances dissolve metals during their use. This, for instance, is the case with lubricating oils, electrical oils, gasolines, etc. When treating such substances with our compounds, it is often desirable to use an amount considerably in excess of that which is required to give it adequate initial protection. In such cases, the proper amounts of the deactivator may if desired be added during the use of the organic substances as may be required from time to time.

We claim as our invention:

1. An organic substance subject to deterioration through oxidation, which substance during its useful life comes in contact with an oxidation promoter selected .from the group consisting of metallic iron, copper, chromium, lead, cobalt and the compounds of copper, chromium, lead and cobalt, containing a small amount of a deactivator having the general formula wherein x represents an aromatic nucleus and Y represents an aliphatic radical having from 2 to 12 carbon atoms inclusive,'and containing a linkage between two carbon atoms of an element selected from the group consisting of oxygen, sulfur and nitrogen other than the nitrogen and oxygen atoms to which said if is attached.

2. An organic substance subject to deterioration through oxidation, which substance during its useful life comes in contact with an oxidation promoter selected from the group consisting of metallic iron, copper, chromium, lead, cobalt and the compounds of copper, chromium, lead and cobait, containing a small amount of ortho salicylai beta beta hydroxy amino di-ethyl imino ether.

8. The substance of claim 1 which contains 4. An organic substance subject to deterioration through oxidation, which substance during its useful life comes in contact with an oxidation promoter selected from the group consisting of metallic iron, copper, chromium, lead, cobalt and the compounds of copper, chromium, lead and cobalt, containing a small amount of a deactivator having the general formula wherein X represents a mono-nuclear aromatic radical and Y represents an aliphatic radical having from 2 to 12 carbon atoms inclusive, and containing a linkage between two carbon atoms of an element selected from the group consisting of oxygen, sulfur and nitrogen other than the nitrogen and oxygen atoms to which said Y is attached.

5. A hydrocarbon fraction containing a, small amount of a deactivator having the general formula wherein X represents an aromatic nucleus and from about 0.01% to about 1% by weight of the I deactivator.

Y represents an aliphatic radical having from 2 to 12 carbon atoms inclusive, and containing a linkage between two carbon atoms of an element selected from the group consisting of oxygen, sulfur and nitrogen other than the nitrogen and.

oxygen atoms to which said Y isattached.

6. The method of increasing the stability of organic substances subject to deterioration through oxidation in contact with oxidation promoters selected from the group consisting of metallic iron, copper, chromium, lead, cobalt and the compounds of copper, chromium, lead and cobalt, which comprises incorporating in said organic substance a small amount of a metallic deactivator having the general formula wherein X represents an aromatic nucleus and Y wherein x represents an aromatic nucleus and Y represents an aliphatic radical having i'rom '2 to 12 carbon atoms inclusive, and containing a linkage between two carbon atoms of an element selected from the group consisting of orwgen, sulfur and nitrogen other than thenitrogen and oxygen atoms to which said Y is attached. a

8. The method of prolonging the useful life oi a hydrocarbon fraction which comprises adding thereto a small amount oi ortho salicyl beta beta hydroxy amino di-ethyl imino ether.

. ELLIS R. WHITE.

IBM L. WALTIRB. 

